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11.
Animals living in extreme environments with predictable seasonality may have important life history events correlated to favourable periods. These animals pass critical life stages in protected habitats, especially during early life, often receiving parental care. It is thus hypothesized that juveniles rely on protective microhabitats provided by their parents, becoming independent only during favourable seasons. Semi-terrestrial crayfish Parastacus pugnax inhabit burrows in highly seasonal and predictable environments, thus being well suited to test this hypothesis. Following marked burrows and individual crayfish we examined the life history patterns of P. pugnax in their natural environment to test the predictions that (i) burrowing activity is higher during the wet season, (ii) reproductive events occur during favourable seasons and (iii) juveniles only disperse after reaching larger sizes. There was little or no burrowing activity during the dry season, when soil was more compact, but burrows became wider and had more openings during the wet season. After hatching, juveniles cohabited with adults for at least 4 months during the dry season. During this period juveniles grew considerably, starting independent lives during the wet season. These results suggest that the prolonged parent-offspring cohabitation evolved in response to the predictable seasonal variations in the crayfish habitat.  相似文献   
12.
Recent clinical evidence supports a link between 25-hydroxyvitamin D insufficiency (serum 25-hydroxyvitamin D [25(OH)D] levels <30 ng/mL) and Parkinson's disease. To investigate the effect of 25(OH)D depletion on neuronal susceptibility to toxic insult, we induced a state of 25(OH)D deficiency in mice and then challenged them with the dopaminergic neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). We found there was no significant difference between control and 25(OH)D-deficient animals in striatal dopamine levels or dopamine transporter and tyrosine hydroxylase expression after lesioning with MPTP. Additionally, we found no difference in tyrosine hydroxylase expression in the substantia nigra pars compacta. Our data suggest that reducing 25(OH)D serum levels in mice has no effect on the vulnerability of nigral dopaminergic neurons in vivo in this model system of parkinsonism.  相似文献   
13.
We assessed the feasibility of using herbarium specimens to validate reference conditions in the UK by comparing diatom community composition of river sites with both recent and historic diatom samples. The question of substrate specificity was addressed by comparing epilithon (stone-derived) and epiphyton (plant-derived) samples from a number of rivers. No significant differences were found between the Trophic Diatom Index (TDI), species richness, species diversity, and percentage of motile valves between paired diatom samples (epilithic and epiphytic) from contemporary samples. Significant differences were recorded between a number of indices derived from analysis of the historic diatom samples on plant material sampled pre-1930 compared with diatoms from stones collected post-1990 from the same river location. The TDI, mean species richness, and species diversity and percentage of motile valves and nutrient tolerant valves were all significantly greater in the contemporary samples (p ≤ 0.05). The percentage of nutrient sensitive valves was significantly lower in the contemporary samples (p ≤ 0.05).The relative abundance of Achnanthidium minutissimum and Cocconeis placentula var. lineata was significantly greater on the herbarium material compared to matched contemporary samples. Calculated values for the TDI (43 ± 3) expected at reference conditions were similar to the observed TDI values derived from herbarium material (44 ± 12) showing no significant deviation in ecological status.  相似文献   
14.
Prostate cancer (PCa) is the most common type of cancer in men in the United States, which disproportionately affects African American descents. While metastasis is the most common cause of death among PCa patients, no specific markers have been assigned to severity and ethnic biasness of the disease. MicroRNAs represent a promising new class of biomarkers owing to their inherent stability and resilience. In the present study, we investigated potential miRNAs that can be used as biomarkers and/or therapeutic targets and can provide insight into the severity and ethnic biasness of PCa. PCR array was performed in FFPE PCa tissues (5 Caucasian American and 5 African American) and selected differentially expressed miRNAs were validated by qRT-PCR, in 40 (15 CA and 25 AA) paired PCa and adjacent normal tissues. Significantly deregulated miRNAs were also analyzed in urine samples to explore their potential as non-invasive biomarker for PCa. Out of 8 miRNAs selected for validation from PCR array data, miR-205 (p<0.0001), mir-214 (p<0.0001), miR-221(p<0.001) and miR-99b (p<0.0001) were significantly downregulated in PCa tissues. ROC curve shows that all four miRNAs successfully discriminated between PCa and adjacent normal tissues. MiR-99b showed significant down regulation (p<0.01) in AA PCa tissues as compared to CA PCa tissues and might be related to the aggressiveness associated with AA population. In urine, miR-205 (p<0.05) and miR-214 (p<0.05) were significantly downregulated in PCa patients and can discriminate PCa patients from healthy individuals with 89% sensitivity and 80% specificity. In conclusion, present study showed that miR-205 and miR-214 are downregulated in PCa and may serve as potential non-invasive molecular biomarker for PCa.  相似文献   
15.
The reptile fauna of Romania comprises 23 species, out of which 12 species reach here the limit of their geographic range. We compiled and updated a national database of the reptile species occurrences from a variety of sources including our own field surveys, personal communication from specialists, museum collections and the scientific literature. The occurrence records were georeferenced and stored in a geodatabase for additional analysis of their spatial patterns. The spatial analysis revealed a biased sampling effort concentrated in various protected areas, and deficient in the vast agricultural areas of the southern part of Romania. The patterns of species richness showed a higher number of species in the warmer and drier regions, and a relatively low number of species in the rest of the country. Our database provides a starting point for further analyses, and represents a reliable tool for drafting conservation plans.  相似文献   
16.
Cystic fibrosis, an autosomal recessive disorder caused by a mutation in a gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR), remains a leading cause of childhood respiratory morbidity and mortality. The respiratory consequences of cystic fibrosis include the generation of thick, tenacious mucus that impairs lung clearance, predisposing the individual to repeated and persistent infections, progressive lung damage and shortened lifespan. Currently there is no cure for cystic fibrosis. With this in mind, we investigated the ability of human amnion epithelial cells (hAECs) to express functional CFTR. We found that hAECs formed 3-dimensional structures and expressed the CFTR gene and protein after culture in Small Airway Growth Medium (SAGM). We also observed a polarized CFTR distribution on the membrane of hAECs cultured in SAGM, similar to that observed in polarized airway cells in vivo. Further, hAECs induced to express CFTR possessed functional iodide/chloride (I−/Cl) ion channels that were inhibited by the CFTR-inhibitor CFTR-172, indicating the presence of functional CFTR ion channels. These data suggest that hAECs may be a promising source for the development of a cellular therapy for cystic fibrosis.  相似文献   
17.
The development and progression of colorectal cancer (CRC) have been associated with inflammation processes that involve the overactivation of the NF‐κB signalling pathway. The characterization of the NF‐κB expression profile in CRC is an important topic since the suppression of NF‐κB represents a potential therapeutic approach. In this study, we assessed the expression levels of 84 NF‐κB‐related genes in paired tumoral (T) and peritumoral (PT) tissues from 18 CRC patients and 18 normal colonic mucosae, and the expression levels of three miRNAs targeting the most dysregulated genes revealed by the case–control analysis. Comparing the gene expression profile of T and controls, 60 genes were dysregulated. The comparison of T and PT revealed 17 dysregulated genes in the tumoral tissues, with IL1B, CXCL8, IL1A, and CSF2 being the most upregulated. Notably, through a bioinformatics analysis, the differential gene expression of 11 out of the 17 genes was validated on a larger cohort of 308 CRC patients compared with 41 controls. Moreover, a decrease in the levels of RELA, NOD1, CASP8, BCL2L1, ELK1, and IKBKB was identified in poorly differentiated tumours compared to moderately differentiated tumours. The analysis of the three miRNAs targeting IL1B, CXCL8, IL1A, and CSF2 showed that miR‐182‐5p was upregulated in T compared with PT, whereas miR‐10b‐5p was downregulated in T compared with PT and control tissues. Our results may contribute to the design of new experimental therapeutic strategies based on endogenous molecules, such as miRNAs, to target the genetic key players of the NF‐ κB pathway.  相似文献   
18.
An epithelial sheet isolated from the trout saccular macula, highly enriched in acousticolateralis receptor cells (hair cells), has been analyzed for primary amine-containing compounds. The hair cell preparation, compared to the saccular nerve, was found to contain elevated levels of the presumptive receptoneural transmitter, glutamate, as well as beta-alanine, and components eluting in the positions of the standards phosphoserine and phosphoethanolamine on cation-exchange HPLC. Saccular nerve contained a different spectrum of primary amines and was elevated specifically in carnosine/homocarnosine. Acid hydrolysis of perchlorate extracts of both hair cell and nerve fractions yielded large amounts of histidine. For the saccular nerve fraction, production of histidine by acid hydrolysis was matched by production of beta-alanine and gamma-aminobutyric acid (GABA) and disappearance of carnosine/homocarnosine. The dipeptides carnosine and homocarnosine have been chromatographically resolved by expanded HPLC and found to be present in saccular nerve in a ratio of approximately 10:1, respectively. Production of histidine in the hair cell extract was not coupled with production of beta-alanine and GABA. The hair cell histidine-containing unknown, present in millimolar concentration, has been identified as N-acetylhistidine by the hydrolysis and rechromatography of fractions from cation-exchange HPLC. The large and specific presence of N-acetylhistidine in the hair cell preparation, together with electrophysiological evidence for its facilitatory action on afferent fibers in the frog semicircular canal, is suggestive of a role for this molecule as well as glutamate in acousticolateralis receptoneural transmission.  相似文献   
19.
The p53 protein is an important factor of many intra- and extracellular processes. This protein regulates the repair of cellular DNA and induces apoptosis. It is also responsible for the regulation of the senescence and the cell entering the subsequent stages of the cellular cycle. The protein p53 is also involved in inhibiting angiogenesis and the induction of oxidative shock. In our study, we examined the activity of p53 protein in the uterine epithelial cells in rats treated with cladribine. Its action is mainly based on apoptosis induction. We compared the activity of p53 protein in cells with a high apoptosis index and in cells with active repair mechanisms and high proliferation index. We observed stronger p53 protein expression in the epithelial cells of the materials taken 24 h after the last dose of 2-CdA associated with the active process of apoptosis and inhibition of proliferation. After 4 weeks from the last dose of cladribine, the stronger expression of p53 protein was associated with both the existing changes in the cell's genome, the effects of the ongoing repair mechanisms, as well as the high proliferation activity.  相似文献   
20.
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